Malicious PDF — malware analysis report

Static analysis result for SHA-256 d657b5e64493854e…

MALICIOUS

PDF

81.7 KB Created: 2021-06-27 07:45:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3bcfb9050e4b5d5cd055144102572f25 SHA-1: 9c849a7ea3a77a546f547b1c5fc3d75379f4a76b SHA-256: d657b5e64493854e9ec8f0ba695349560d60d3c0d48721659cf838290281e904
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It functions as a link farm, containing numerous URLs pointing to compromised CMS uploads and disposable hosting, likely to obscure the ultimate destination. The presence of multiple PDF link farm heuristics and the ML detection strongly suggest a malicious intent to redirect users to harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://cbolean.com/wp-content/plugins/super-forms/uploads/php/files/6jk5ecg1mmi5u5rvk8kvagju51/61874270695.pdf
    • https://autosofortkauf.ch/wp-content/plugins/super-forms/uploads/php/files/j5gvldnolkfd89qeert6s3lf38/kotugeburevujalumuxozabuw.pdf
    • http://escolacaritas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160932c64b6b70---wasakubutizamapilusam.pdf
    • https://alsterparkett.de/wp-content/plugins/super-forms/uploads/php/files/e0s3aad1ut18g19oomgpi8mbmk/basafidasubopi.pdf
    • https://mangmalungtea.com/userfiles/file/kinakebefitipizonaw.pdf
    • http://claphamtaxi.com/survey/userfiles/files/92673528425.pdf
    • http://www.dnevi-sekretarjev.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160b1e25c9bda0---sasafe.pdf
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087b09578140---33134084945.pdf
    • http://brmhn.com/userfiles/file/20210519122923_jjgsbm.pdf
    • https://funkydrop.shop/wp-content/plugins/super-forms/uploads/php/files/20fd8d0ff7d3768f1382dd22f7a2f2e9/97687767091.pdf
    • http://www.ddd-iasi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160965d4254a2c---bejimokegukaredibeku.pdf
    • https://nhaban24h.com.vn/wp-content/plugins/super-forms/uploads/php/files/ndfadc08tsdfp4d1u7trlqnf2c/34397000518.pdf
    • https://ajitcoatings.com/uploads/petimudarovixojofagufu.pdf
    • https://certifiedmoversinc.com/wp-content/plugins/super-forms/uploads/php/files/d8740b791fb6d52671caba8d5e9b8386/mugemekovulagumedazibese.pdf
    • https://k-kompany.ru/wp-content/plugins/super-forms/uploads/php/files/a3915023c3738a28579bef0923f2f19c/41435908169.pdf
    • https://pt2-turbo-j3t.com/contents//files/zebapi.pdf
    • https://agenciaboom.com/wp-content/plugins/super-forms/uploads/php/files/4kftfcuu08g67brcgm0s0vm007/23984674501.pdf
    • https://moniimpex.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b75b1877c98---51721757294.pdf
    • http://www.marcado.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16096ec20167bf---zamibitezalisezixu.pdf
    • https://bakotech.at/uploads/ckeditor/files/77744306727.pdf
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/160afa523d0e44---tikifuguwapuliju.pdf
    • http://forter.vn/hinhanh/file/dawulusubofu.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=logo+quiz+answers+level+13+android
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dcb0.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDCB0 16792 bytes
font_01_sfnt_off0000f4c2.bin
8ca84153b23f5cf176a457c311f3451a79ebd35536ca3945e571a8b13b868e2d
pdf-font-stream PDF embedded font (sfnt) at offset 0xF4C2 16796 bytes
font_02_sfnt_off0001204a.bin
90b41a34098e16329ca064635a17b5a4973da26a73793b5525b7c0bea7d586c4
pdf-font-stream PDF embedded font (sfnt) at offset 0x1204A 10964 bytes